<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../react18/react.development.js"></script>
  <script src="../react18/react-dom.development.js"></script>
  <script src="../react18/babel.min.js"></script>
  <script src="../react18/prop-types.js"></script>
</head>

<body>
  <div id="app"></div>
  <script type="text/babel">

    /* 
      props是用来做父子组件通信的
        -在父组件中使用子组件的时候,可以给子组件添加属性
        -在子组件中组件实例的props属性上,就能拿到这个属性和值
    */

 class Parent extends React.Component{
  state={
    car:"八手奥拓"
  }

  render(){
    const{car}=this.state;
    return (
      <div>
        <h1>我是父组件</h1>
        <p>我开的车是{car}</p>
        <hr/>
        <Child a={1} car={car}/>
        </div>
    )
  }
 }

 class Child extends React.Component{
 
  render(){
    const{car}=this.props
    return (
      <div>
        <h1>我是子组件</h1>
        <p>我开的车是{car}</p>
        <hr/>
        </div>
    )
  }

  static propTypes={
    a:PropTypes.number.isRequired,
    car:PropTypes.string
  }
 }

 const root=ReactDOM.createRoot(document.getElementById('app'))
 root.render(<Parent/>)


  </script>
</body>

</html>